6
4 Wiring
4.1 Connecting GND
Device GND connection helps ensure device lightning protection and anti-interference. You should
connect the GND cable before powering on the device, and power off the device before
disconnecting the GND cable. There is a GND screw on the device cover board for the GND cable. It is
called enclosure GND.
Figure 4-1 GND port
Step 1
Remove the GND screw from the enclosure GND with a cross screwdriver.
Step 2
Connect one end of the GND cable to the cold-pressed terminal, and attach it to the
enclosure GND with the GND screw.
Step 3
Connect the other end of the GND cable to the ground.
The sectional area of the GND cable must be more than 2.5 mm
2
, and the GND resistance
must be less than 4 Ω.
4.2 Connecting Power Cord
Models with PoE support two power inputs: PWR1 and PWR2. You can select a backup power supply
to ensure power is continuously provided, even if one channel of power breaks down. This greatly
improves the reliability of network operations. Models without PoE only support power supplies
through 12 VDC power adapters.
To avoid personal injury, do not touch any exposed wires, terminals or areas of the device that have
dangerous voltage levels. Do not dismantle parts or plug connectors into the device during power
on.
Before connecting power, make sure that the power supply conforms to the power supply
requirements on the device label. Otherwise, it might cause device damage.
The sectional area of the power cable must be more than 0.75 mm
2
(maximum sectional area 2.5
mm
2
); ground resistance is required to be less than 4 Ω.